The invention relates to an improved multiple bolt combination lock.
Combination locks have been in wide use for many years. Basically, such locks include an accessible dial which can be manually rotated and which includes a shaft which rotates with the dial. A cam wheel is mounted for rotation with the shaft and engages a plurality of locking wheels, each of which has a slot defining a gate and each of which is freely rotatable about the dial shaft. When the gates of the wheels are aligned by manual rotation of the dial in opposite directions to prescribed positions, which positions define the combination, a latch or some other mechanism shifts its position to permit the bolts to be withdrawn from their latching positions.
The bolts are conventionally withdrawn by operation of a separate mechanism, usually a handle which rotates to move the bolts.
The present invention relates to an improved and simplified combination lock in which no separate mechanism for retracting the locking bolts is required. Rather, when the lock has been manually manipulated to a position with the cam and locking wheels properly aligned, a lever arm drops into the gates under the urging of a spring and couples for rotation with the dial the top and bottom pans of the lock between which the wheel post and wheels are mounted. On the outer surface of the top pan, the lock bolts are pivotably fixed at a location separated from the center of rotation thereof. Thus, continued rotation of the manual dial after the correct combination has been reached and the cam and wheels properly aligned, operates to retract the bolts. Rotation of the dial subsequently in the opposite direction returns the bolts to the latching position. A cam member on the wheel post which preferably extends through a slot in the bottom pan engages the lever arm to cam the lever arm out of the slots when the bolts have been returned to the locking position so that the above steps may be repeated to retract the bolts and open the lock.